By Authority Of
THE UNITED STATES OF AMERICA
Legally Binding Document
By the Authority Vested By Part 5 of the United States Code § 552(a) and
Part 1 of the Code of Regulations § 51 the attached document has been duly
INCORPORATED BY REFERENCE and shall be considered legally
binding upon all citizens and residents of the United States of America.
HEED THIS NOTICE : Criminal penalties may apply for noncompliance.
Document Name: SAE J386: Operator Restraint Systems for Off-Road
Standards Body: Society of Automotive Engineers
SEAT BELTS FOR CONSTRUCTION EQUIPMENT
SEAT BELTS FOR
CONSTRUCTION EQUIPMENT— SAE J386
SAE Recommended Practice
Report of Construction and Industrial Machinery Technical Committee approved March 1969.
1. Purpose— The purpose of this recommended practice is to estab-
lish minimum requirements for a pelvic restraint belt suitable' for use
primarily on track-type tractors, wheel tractor-scrapers, wheel loaders,
motor graders, and similar types of construction equipment.
2. Scope— This recommended practice covers the general require-
ments for webbing, buckle hardware, adjustment hardware, and attach-
ment hardware of the restraint system. It does not include the method
or direction of attachment to the vehicle or seat assembly.
3.1 Type 1 System— Lap belt only for pelvic restraint,
3.2 Type 2 System— Combination of pelvic and upper torso re-
3.3 Hardware— Any metal or rigid plastic part of the seat belt as-
3.4 Polyester Fiber— Any long chain synthetic polymer composed
of at least 85% by weight of an ester of a dihydric acid and tereph-
3.5 Roping— The tendency of a piece of webbing to twist upon it-
self and remain in the form of a rope instead of returning to its
original strap, form.
3.6 Model or Style Number— Identification of a seat belt assembly
consisting of a single combination of webbing having a specific type
of fiber, weave, and construction, and hardware having a specific
4. General Requirements
4.1 Single Occupancy— A seat belt shall be designed for use by one,
and only one, person at any one time.
4.2 Pelvic Restraint— A seat belt shall provide pelvic restraint
whether or not upper torso restraint is provided. The seat belt shall
also be designed to secure the pelvis and remain in the pelvic area
under operating, collision, or roll-over conditions.
4.3 Hardware— All hardware parts which contact, under normal
usage, a person, clothing, or webbing shall be free from burrs and
4.4 Release— The seat belt shall be provided with a buckle or
buckles readily accessible to the occupant to permit his easy and rapid
removal from the assembly. The buckle release mechanism shall be
designed to minimize the possibility of accidental release.
4.5 Adjustment— The seat belt shall be capable of snug adjustment
by the occupant by a means easily within his reach, or shall be provided
with an automatic locking or emergency locking retractor. The ad-
justment range shall accommodate the 5th through the 95th percentile
American male (SAE J833).
4.6 Marking— Each seat belt shall be permanently and legibly .
marked or labeled with year of manufacture, model or style number,
and name or trade mark of manufacturer or distributor, or of the im-
porter if manufactured outside of the United States.
4.7 Usage and Maintenance Instructions— Seat belts shall be ac-
companied by written instructions to the installer for the proper use
of wearing the belt snugly and properly located on the body and for
the maintenance of the belt, including periodic inspection of all com-
ponents. The instructions shall show the proper manner of threading
the webbing in the hardware of seat belts in which the webbing is not
4.8 Assembly Performance— The seat belt shall meet all the re-
quirements for assembly performance listed in SAE J4c.
5. Webbing Requirement's
5.1 General— The webbing shall meet the applicable requirements
of SAE J4c.
5.2 Material— The webbing material shall have a resistance to
acids, alkalies, mildew, aging, moisture, and sunlight equal to or bet-
ter than that of untreated polyester fiber.
5.3 Stiffness— To minimize "roping," the webbing shall be woven
and/or treated to produce a stiffness in the transverse direction equal
to or greater than that obtained with a weave of double plain with one
up, one down binder without stuffers. This stiffness shall be effective
for the usable life of the webbing. The webbing shall be flexible in
the longitudinal direction to permit adjustment down to —40 F.
5.4 Color— The color black is preferred since it is least affected by
exposure to ultraviolet light.
5.5 Width— The webbing shall be not less than 1.8 in. (46 mm) in.
width when measured as specified in SAE J4c.
5.6 Strength-The webbing shall have not less than 6000 lb (2720
kg) breaking strength when tested by the procedures specified in SAE
5.7 Elongation— The webbing shall not extend to more than 15%
at 2500 lb (1130 kg) when subjected to the specified forces in accor-
dance with the procedures specified in SAE J4c.
5.8 Resistance to Abrasion— The webbing shall have a breaking
strength not less than 75% of the strength before abrasion when
tested in accordance with SAE J4c.
5.9 Ends— The ends of the webbing shall be protected or treated
to prevent unraveling, and shall not pull out of the adjustment hard-
ware at the maximum size adjustment.
6. Buckle Hardware Requirements
6.1 General— The buckle hardware shall meet all of the applicable
requirements of SAE J4c.
6.2 Release— The buckle shall be designed so that it can be easily
released with a single motion. It shall also be capable of being released
with either available mittened hand.
6.3 Closure— The buckle shall be designed so that it can be easily
closed with mittened hands.
6.4 Size— The buckles should be as wide as the webbing width and
shall not present any rougher surface between the belt and the buckle .
than a doubled back thickness of the webbing when the assembly is
loaded in accordance with the standard loop test (see SAE J4c).
6.5 Padding-=-If a buckle is used which is less than the width of
the webbing, a pad must be provided. This pad must cover the entire
buckle area and be the full width of the webbing. It must be made of
a material having properties equal to or better than that stated in
paragraph 5.2 and must be permanently fastened to the assembly so
that it is not injurious or uncomfortable to the operator.
7. Adjustment Hardware Requirements
7.1 General— The adjustment hardware shall meet all the ap-
plicable requirements of SAE J4c.
7.2 Location— When a two-piece belt is used, the adjustment means
shall be on each half of the belt to allow for the centering of the
buckle on the operator.
7.3 Operation— Each adjustment shall be capable of being made
with the use of one mittened hand.
5. Attachment Hardware Requirements— The attachment hardware
shall meet all the applicable requirements of SAE J4c.